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1.
地形地貌是岩性解译的重要信息,地形因子作为描述DEM数字曲面几何特征的定量指标参数,可用来定量化表达不同岩性所在地区地形地貌特征。本文以桂林-阳朔地区为研究区,研究地形因子数学、地质意义,建立岩性与地形因子组合间的定量关联,进而实现岩石类型划分。本文基于ASTERGDEM提取坡度、起伏度等12个地形因子,在分析各个地形因子地质意义基础上,通过聚类分析及方差分析的多元统计分析方法,研究各岩性地形因子特性及其关联性,建立研究区岩性之间的定量差异;此外,利用因子分析方法研究岩性分类过程中的主导因素,确定适宜岩性分类方法以实现定量化岩性分类。实验结果表明:不同岩性、不同地形地貌的地形因子(组合)之间具有显著差异,基于因子分析得到的宏观地形复杂度指数(MTI)以及微观曲率指数(MCI)对岩石类型的分类精度达77.36%。研究表明,地形复杂度等地形因子可用于岩性分类,采用因子分析方法可获取反映地形地貌宏观、微观特征的定量指标,且岩性分类效果良好。 相似文献
2.
This issue presents proceedings of the "Stars and Interstellar Medium" section of the AllRussian Astronomical Conference VAK-2017. Sixteen papers(selected from about 70 talks) cover different problems related to stars, pulsars, interstellar gas and dust, and star formation. The preface briefly reviews these papers. 相似文献
3.
Astronomy Letters - The sensitivity of future far-infrared telescopes, such as Millimetron, will be limited by the confusion noise produced by distant galaxies. We have constructed a model of the... 相似文献
4.
Muryshev K. E. Eliseev A. V. Denisov S. N. Mokhov I. I. Arzhanov M. M. Timazhev A. V. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(3):235-241
Izvestiya, Atmospheric and Oceanic Physics - The phase shift between changes in the global surface temperature Tg and atmospheric CO2 content $${{q}_{{{\text{C}}{{{\text{O}}}_{2}}}}}$$ has been... 相似文献
5.
Creating an isotopically similar Earth–Moon system with correct angular momentum from a giant impact
Bryant M. Wyatt Jonathan M. Petz William J. Sumpter Ty R. Turner Edward L. Smith Baylor G. Fain Taylor J. Hutyra Scott A. Cook John H. Gresham Michael F. Hibbs Shaukat N. Goderya 《Journal of Astrophysics and Astronomy》2018,39(2):26
The giant impact hypothesis is the dominant theory explaining the formation of our Moon. However, the inability to produce an isotopically similar Earth–Moon system with correct angular momentum has cast a shadow on its validity. Computer-generated impacts have been successful in producing virtual systems that possess many of the observed physical properties. However, addressing the isotopic similarities between the Earth and Moon coupled with correct angular momentum has proven to be challenging. Equilibration and evection resonance have been proposed as means of reconciling the models. In the summer of 2013, the Royal Society called a meeting solely to discuss the formation of the Moon. In this meeting, evection resonance and equilibration were both questioned as viable means of removing the deficiencies from giant impact models. The main concerns were that models were multi-staged and too complex. We present here initial impact conditions that produce an isotopically similar Earth–Moon system with correct angular momentum. This is done in a single-staged simulation. The initial parameters are straightforward and the results evolve solely from the impact. This was accomplished by colliding two roughly half-Earth-sized impactors, rotating in approximately the same plane in a high-energy, off-centered impact, where both impactors spin into the collision. 相似文献
6.
N. A. Shulga 《Oceanology》2018,58(5):672-678
This work presents the first results of a comparative study on the composition and distribution of organic matter (OM) (TOC, n-alkanes, pristane, phytane) in ferromanganese nodules and underlying sediments (0–1 cm) from three sites within the Clarion–Clipperton Fracture Zone, Pacific Ocean. Samples were collected during Cruise 120 of the RSS James Cook in 2015. The studied nodules differ in size, shape, and morphology. The TOC content in the nodules is 0.15% on average with insignificant variations which is less than in the sediments. The molecular composition of n-alkanes in the nodules is mainly determined by modern bacterial activity with high preservation of terrigenous n-alkanes in the environment of the ore deposit formation. 相似文献
7.
8.
S.?N.?KulichkovEmail author O.?Ye.?Popov K.?V.?Avilov I.?P.?Chunchuzov O.?G.?Chkhetiani A.?A.?Smirnov V.?I.?Dubrovin A.?A.?Mishenin 《Izvestiya Atmospheric and Oceanic Physics》2018,54(3):293-303
Results obtained from simulating the propagation of infrasonic waves from the Chelyabinsk meteoroid explosion observed on February 15, 2013, are given. The pseudodifferential parabolic equation (PDPE) method has been used for calculations. Data on infrasonic waves recorded at the IS31 station (Aktyubinsk, Kazakhstan), located 542.7 km from the likely location of the explosion, have been analyzed. Six infrasonic arrivals (isolated clearly defined pulse signals) were recorded. It is shown that the first “fast” arrival (F) corresponds to the propagation of infrasound in a surface acoustic waveguide. The rest of the arrivals (T1–T5) are thermospheric. The agreement between the results of calculations based on the PDPE method and experimental data is satisfactory. The energy E of the explosion has been estimated using two methods. One of these methods is based on the law of conservation of the acoustic pulse I, which is a product of the wave profile area S/2 of the signal under analysis and the distance to its source E I [kt] = 1.38 × 10–10 (I [kg/s])1.482. The other method is based on the relation between the energy of explosion and the dominant period T of recorded signal E T [kt] = 1.02 × (T [s]2/σ)3/2, where σ is the dimensionless distance determining the degree of nonlinear effects during the propagation of sound along ray trajectories. According to the data, the explosion energy E I,T ranges from 1.87 to 32 kt TNT. 相似文献
9.
10.
V.?L.?Afanasiev Yu.N.?GnedinEmail author M.Yu.?Piotrovich S.?D.?Buliga T.?M.?Natsvlishvili 《Astronomy Letters》2018,44(6):362-369
Based on spectropolarimetry for 47 type 1 active galactic nuclei observed with the 6-m BTA telescope, we have estimated the spins of the supermassive black holes at the centers of these galaxies. We have determined the spins based on the standard Shakura–Sunyaev accretion disk model. About 70% of the investigated active galactic nuclei are shown to have Kerr supermassive black holes with a dimensionless spin greater than 0.9. 相似文献